<template>
	<view>
		<view class="search-box">
      <uni-search-bar @input="input" :radius="100" cancelButton='none'></uni-search-bar>
    </view>
    
    <!-- 搜索建议列表 -->
    <view class="sugg-list" v-if="searchResults.length !== 0 ">
      <view class="sugg-item" v-for="(item, i) in searchResults" :key="i" @click="gotoDetail(item)">
        <view class="goods-name"> {{item.goods_name}}</view>
          <uni-icons type="arrowright" size="30"></uni-icons>
      </view>
    </view>
    
    <!-- 搜索历史 -->
    <view class="history-box" v-else>
      <!-- 标题区 -->
      <view class="history-title">
        <text>搜索历史</text>
        <uni-icons type="trash" size="17" @click="clean"></uni-icons>
      </view>
      <!-- 列表区域 -->
      <view class="history-list">
        <uni-tag :text="item" v-for="(item,i) in histories" :key="i" @click="gotoGoodsList(item)"></uni-tag>
      </view>
    </view>
	</view>
</template>

<script>
	export default {
		data() {
			return {
        //延时器的timerId的防抖
				timer: null,
        //搜索关键词
        kw: '',
        //搜索的结果列表
        searchResults: [],
        //搜索历史的数组
        historyList: []
			};
		},
    methods: {
      //input输入事件的处理函数
      input(e){
        clearTimeout(this.timer)
        
        this.timer = setTimeout(() => {
          this.kw = e.value
          this.getSearchList()
        },500)
      },
      async getSearchList(){
        //判断搜索关键词是否为空
        if(this.kw.length === 0){
          this.searchResults = []
          return
        }
        
        const {data: res} = await uni.$http.get('/api/public/v1/goods/qsearch',{query: this.kw})
        if(res.meta.status !== 200) return uni.$showMsg()
        this.searchResults = res.message
        
        this.saveSearchHistory()
      },
      gotoDetail(item) {
        uni.navigateTo({
          url: '/subpkg/goods_detail/goods_detail?goods_id=' + item.goods_id
        })
      },
      saveSearchHistory() {
        // this.historyList.push(this.kw)
        
        //1.将Array数组转化为Set对象
        const set = new Set(this.historyList)
        //2.调用Set对象的delete方法，移除对应的元素
        set.delete(this.kw)
        //3.调用Set对象的add方法，向Set中添加元素
        set.add(this.kw)
        //4.将Set对象转化为Array数组
        this.historyList = Array.from(set)
        
        //调用uni.setStorageSync(key,value) 将搜索历史记录持久化存储到本地
        uni.setStorageSync('kw',JSON.stringify(this.historyList))
    },
    clean() {
      this.historyList = []
      uni.setStorageSync('kw','[]')
    },
    gotoGoodsList(kw) {
      uni.navigateTo({
        url: '/subpkg/goods_list/goods_list?query=' +kw
      })
    }
	},
  computed: {
    histories() {
      //注意：由于数组是引用类型，所以不要直接基于原数组调用reverse 方法，以免修改原数组中元素的顺序
      //而是应该新创建一个内存无关的数组，在进行reverse反转
      return [...this.historyList].reverse()
    }
  },
  onLoad() {
    this.historyList = JSON.parse(uni.getStorageSync('kw') ||'[]')
  }
  }
</script>

<style lang="scss">
.search-box {
  position: sticky;
  top: 0;
  z-index: 999;
}

.sugg-list{
  padding: 0 5px;
  .sugg-item{
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 12px;
    padding: 13px 0;
    border-bottom: 1px solid #efefef;
    .goods-name{
      //文字不允许换行（单行文本）
      white-space: nowrap;
      //溢出部分隐藏
      overflow: hidden;
      //文本溢出后用 ... 代替
      text-overflow: ellipsis;
      margin-right: 3px;
    }
  }
}

.history-box {
  padding: 0 5px;
  .history-title {
    display: flex;
    justify-content: space-between;
    height: 40px;
    align-items: center;
    font-size: 13px;
    border-bottom: 1px solid #efefef;
  }
  .history-list {
    display: flex;
    flex-wrap: wrap;
    
    .uni-tag {
      margin-top: 5px;
      margin-right: 5px;
    }
  }
}
</style>
